Interdiffusion in Polyimide Thin Films

1986 ◽  
Vol 72 ◽  
Author(s):  
E. J. Kramer ◽  
W. Volksen ◽  
T. P. Russell
Keyword(s):  
Thin Films ◽  
Diffusion Coefficient ◽  
Silicon Substrate ◽  
Diffusion Coefficients ◽  
Depth Profiling ◽  
Tracer Diffusion ◽  
Polyamic Acid ◽  
Diffusion Temperature ◽  
Tracer Diffusion Coefficients ◽  
Large Diffusion

AbstractThe interdiffusion in thin films of polyimide has been investigated using the forward recoil spectrometry (FRES) technique. Films 5–10 μm in thickness of polyamic acid spin coated onto a silicon substrate were imidized at a temperature TI. A second film, ∼300Å in thickness of perdeuterated polyamic acid was spin-coated onto the first layer and heated to a temperature TD to allow interdiffusion of the two films and imidization of the second coating. Depth profiling of the deuterated polymer by FRES showed that no interdiffusion occurred if TI>TD and TI>200°C. Substantial interdiffusion occurred if TD>TI and TI<400° C. Time averaged tracer diffusion coefficients were found to vary with the TD and TI, as well as the length of time allowed for interdiffusion. Since conversion of the deuterated polyamic acid to polyimide occurs at the diffusion temperature, the results are consistent with a relatively large diffusion coefficient for the polyamic acid (D>2.5× 10−14 cm2/sec) which decreases to a negligible value as the molecule is fully converted to the corresponding polyimide.

Temperature dependence of tracer diffusion coefficients in polystyrene

1986 ◽  
Vol 1 (1) ◽  
pp. 202-204 ◽  
Author(s):  
Peter F. Green ◽  
Edward J. Kramer
Keyword(s):  
Molecular Weight ◽  
Diffusion Coefficient ◽  
Shear Rate ◽  
Temperature Dependence ◽  
Diffusion Coefficients ◽  
Tracer Diffusion ◽  
Tracer Diffusion Coefficient ◽  
Critical Molecular Weight ◽  
Tracer Diffusion Coefficients ◽  
Monomeric Friction Coefficient

The temperature dependence of the tracer diffusion coefficient D* of long deuterated polystyrene (d-PS) chains of molecular weight M>Mc, where Mc is the critical molecular weight for entanglement, diffusing into highly entangled PS matrices, each of molecular weight P = 2×107, is studied using forward recoil spectrometry. It is found that the temperature dependence of D*/T, reflected primarily in the monomeric friction coefficient, is accurately described by a Vogel equation. The constants that are used to fit these results are independent of M and are the same as those used to fit the temperature dependence of the zero shear rate viscosity of polystyrene.

Non-Stoichiometry and Cation Tracer Diffusion Studies in the Magnetite-UlvÖSpinel Solution, (Fe,Ti)3-δO4

1994 ◽  
Vol 369 ◽  
Author(s):  
Sanjeev Aggarwal ◽  
Rudiger Dieckmann
Keyword(s):  
Diffusion Coefficients ◽  
Tracer Diffusion ◽  
Oxygen Activity ◽  
Spinel Solid Solution ◽  
Low Oxygen ◽  
Cation Diffusion ◽  
Deviation From Stoichiometry ◽  
Diffusion Studies ◽  
Tracer Diffusion Coefficients ◽  
Point Defect Structure

AbstractCation diffusion in the spinel solid solution (Fe1-xTix)3-δO4 (0≤ x ≤ 0.3) was investigated at 1200 ºC as a function of oxygen activity, aO2 and cationic composition, x. At different cationic compositions, cation tracer diffusion coefficients, D*Me of Me = Fe and Ti were measured as a function of oxygen activity. Plots of log DMe vs. loga0 show V-shaped curves, indicating that different types of point defects prevail at high anc low oxygen activities. Thermogravimetric experiments were conducted, using a high resolution microbalance, to determine the deviation from stoichiometry in (Fe1-xTix)3-δO4 at 1200 °C. δversus log aO2 curves are S-shaped. An analysis of the oxygen activity dependences of thecation diffusion coefficients and the deviation from stoichiometry with regardto the point defect structure suggests that at high oxygen activities cation vacancies are the predominant defects governing the deviation from stoichiometry and the diffusion ofcations. At low oxygen activities, and at small values of x, cation interstitials determine the deviation from stoichiometry, while they dominate for 0 ≤ x ≤ 0.3 inthe cation diffusion.

Oxygen diffusion in amorphous and partially crystalline gallium oxide

2019 ◽  
Vol 21 (8) ◽  
pp. 4268-4275 ◽  
Author(s):  
Alexandra von der Heiden ◽  
Manuel Bornhöfft ◽  
Joachim Mayer ◽  
Manfred Martin
Keyword(s):  
Activation Energy ◽  
Diffusion Coefficients ◽  
Low Temperatures ◽  
Oxygen Diffusion ◽  
Gallium Oxide ◽  
Tracer Diffusion ◽  
Tof Sims ◽  
Tracer Diffusion Coefficients ◽  
Oxygen Tracer

We established a TTT diagram of crystallisation of gallium oxide. Determination of oxygen tracer diffusion coefficients by IEDP/ToF-SIMS allowed us to access the activation energy for amorphous GaO1.5 at low temperatures.

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